1998 GMC 4.3 TWO WHEEL DRIVE I KEEP GRTTING THIS CODE

Location

https://www.google.com/search?q=2006+gmc+canyon+canister+purge+valve+location

The Codes

P0455 GMC Code - Evaporative Emission Control System ...

https://www.engine-codes.com > p0455_gmc
P0455 GMC Code - Evaporative Emission Control System Leak Detected Gross Leak · Possible Causes · How To Fix · Tech Notes ? · Cost to Diagnose · Meaning.

P0442 GMC Code Evaporative Emission Control System Leak ...

https://www.autocodes.com > p0442_gmc
Aug 17, 2017 - The P0442 code means that the control module has detected a small leak in the Evaporative Emission (EVAP). Loose fuel tank filler cap is the ...

Your not going to inspection obviously, without
checking for OBD Codes & making sure all
Emission Monitors run, or you just waste your time
as usual, sitting in line to fail

TYPE: OBD PO452 to see your codes

Going to have to component test the Evap System
& find the problem & resolve

this refers to the emission control system, namely the evaperative control side of the system , it may just be a case of tightening the gas cap so it clicks a couple of times , if not tight enough the pressure in the gas tank falls and is detected as a leak to the atmosphere of gas fumes , if tightening cap doesnt cure the fault code i'd get a new cap as a cheap place to start , dont forget to get the code wiped then tighten cap then re-read codes after a short drive hope this helps

p0449 is an evaporative emission code that indicates a problem with the canister vent solenoid.. without being able to scan and check all of the system I would recomend replacing the vent solenoid. I believe their was a GM TSB on that part and it has been modified.
please respond with fix details

Problem in the shifter or transfer case. Bring it to a transmission repair shop. they do the diagnosis and repair in their sleep.

More than likely ..electric motor on transfer case.....(this is what activates your front drive shaft in conjunction with another actuator to engage the front axle for 4x4 operation)....... malfunction

it could be a vacuum line leak, or the vacuum actulator, also check to see if you have oil in the vacuum line under the truck if you do it would be the vacuum switch on the top of the tansfer case.

there is a lock who mainteins the 4 wheel lock ,so you must change that or adjust that.

there is something wrong with you 4wd system might be electrial problem get it check be gmc service tech for diag code

check the control module located behind pass.side kick panel undo connector plug youll find corrosion on 2pins clean them ,